The present invention relates to a bearing assembly which is capable of attaining high load capabilities while maintaining low power losses for both flooded and starved conditions.
Hydrodynamic bearings in the form of pillow blocks have been used for at least a hundred years and still remain in wide use as lubricated bearing systems for general applications. Initially, such bearings were utilized for relatively low-speed operations at moderate radial and thrust loads. More recently, however, the range of use of such bearings has been extended due to the introduction of new lubricants, improvements in oil delivery systems, overall improvements to bearing efficiency, and the like.
Hydrodynamic bearings depend on positive pressure generation of an oil film for successful operation. In considering proper bearing operation, many factors come into play such as film thickness, lubricant temperature, operational speeds, load, and the like.
Generally speaking, bearing operations may vary considerably under different operating conditions such as the parameters noted above, and a bearing; designed for one particular set of operating conditions may not perform effectively for a different set of conditions. Heretofore, such differences have led manufacturers to generally design separate bearing assemblies for specific operational parameters. Such, of course, increases not only the expense of an individual bearing assembly, but also requires the manufacturer to maintain significant inventories to meet the needs for each separate application.
It has been stated that a bearing should be capable of operation at maximum load capabilities with minimum power losses under both flooded and started lubricant conditions. The bearing system according to the present invention approaches the aforementioned optimized bearing operation. Particularly, bearings according to the present invention have the ability to carry both radial and thrust loads at reduced power losses under both fluid film starved and flooded conditions. Furthermore, the bearing system of the present invention may be presented in a self-contained unit that requires very little maintenance, and in the same form can utilize an external source of lubricant and/or an internal circulating lubricant system.